What evidence is there on this scan to suggest a cause for his symptoms?
The right middle cerebral artery (MCA) is markedly brighter than the surrounding tissue, and brighter in comparison to the left MCA. Brightness on a CT is described as being "hyperdense". (This is best seen on slices 8 and 9.)
What does a "hyperdense MCA" suggest?
This is likely to be acute blood products (thrombus/emboli) sitting in the right MCA. Although there are few changes in the brain parenchyma, with this scan and the presentation, this is in keeping with an acute stroke.
Why is the time of onset important in cases like this?
Best practice would recommend thrombolysis in non-haemorrhagic strokes. The risk-benefit results are time dependent, with current guidance for it to be given within 4.5 hours from onset of symptoms. All these cases should be discussed with stroke consultants on call who can authorise this treatment.
Hyperdense right MCA.
There is subtle loss of gray-white mater interface in the right basal ganglia (blurred basal ganglia sign). Also, insular ribbon sign is seen.
No evidence of haemorrhage.
Calcification at both internal carotid arteries at the bottom of the scan.